Indonesian pavilion in 1964 New York World Fair and Tugu Nasional (National Obelisk) were built in the same period of Nation-Building Projects through the same collaboration work of President Sukarno (as the patron) and Soedarsono (as the architect). Both buildings displayed several similarities as the result of the nature of Sukarno and Soedarsono work method. The purpose of the study, through the comparison, is to get further description about the architecture of Indonesian pavilion. It is identified that Indonesian Pavilion was an identical twin of Tugu Nasional that created to live in and for different environment.